Yes, that was an impromptu video and wasn't planned. Though I had planned the tech session at the meeting, there were no plans for the video. TopNotch just decided to video at the last moment, with his phone, I believe.
The reason for cutting away the old dew wipe is because it's usually brittle and broken and of no use. It makes access to those little screws much easier. The new dew wipe is soft and supple and will allow you to get your fingers and dew wipe tool in there to replace the screws.
Usually the inner felt pads are good since they aren't exposed to the rain and dirt that the outer pads encounter. Unless they are scratching the inside of the window, I really see no need for replacement.. The inner seal is essentially to keep out noise and any air that might be forced into the door through drains, door handles and trim pieces.